A stromatolite from Mauritania

Part of Hall of Planet Earth.

A Stromatolite From Mauritania AMNH/R.Mickens

An entire colony of microbes piled on one another over time, forming semi-rigid, upward-pointing, and branching columns mirrored in this 900-million-year-old stromatolite. Eventually, the structure was buried by slowly accumulating carbonate muds, visible here as the gray rock between the branches.

Gift from the Islamic Republic of Mauritania